xref: /freebsd/sys/dev/qcom_clk/qcom_clk_fdiv.c (revision 911f0260390e18cf85f3dbf2c719b593efdc1e3c)
1 /*-
2  * Copyright (c) 2021 Adrian Chadd <adrian@FreeBSD.org>.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/bus.h>
32 #include <sys/lock.h>
33 #include <sys/mutex.h>
34 #include <sys/rman.h>
35 #include <machine/bus.h>
36 
37 #include <dev/extres/clk/clk.h>
38 #include <dev/extres/clk/clk_div.h>
39 #include <dev/extres/clk/clk_fixed.h>
40 #include <dev/extres/clk/clk_mux.h>
41 
42 #include "qcom_clk_fdiv.h"
43 
44 #include "clkdev_if.h"
45 
46 /*
47  * This is a fixed divisor node.  It represents some divisor
48  * that is setup by the boot environment and we don't have
49  * any need for the driver to go and fiddle with.
50  *
51  * It likely should just live in the extres/clk code.
52  */
53 
54 struct qcom_clk_fdiv_sc {
55 	struct clknode	*clknode;
56 	uint32_t divisor;
57 };
58 
59 static int
60 qcom_clk_fdiv_recalc(struct clknode *clk, uint64_t *freq)
61 {
62 	struct qcom_clk_fdiv_sc *sc;
63 
64 	sc = clknode_get_softc(clk);
65 
66 	if (freq == NULL || *freq == 0) {
67 		printf("%s: called; NULL or 0 frequency\n", __func__);
68 		return (ENXIO);
69 	}
70 
71 	*freq = *freq / sc->divisor;
72 	return (0);
73 }
74 
75 static int
76 qcom_clk_fdiv_init(struct clknode *clk, device_t dev)
77 {
78 	/*
79 	 * There's only a single parent here for an fixed divisor,
80 	 * so just set it to 0; the caller doesn't need to supply it.
81 	 */
82 	clknode_init_parent_idx(clk, 0);
83 
84 	return(0);
85 }
86 
87 static clknode_method_t qcom_clk_fdiv_methods[] = {
88 	/* Device interface */
89 	CLKNODEMETHOD(clknode_init,		qcom_clk_fdiv_init),
90 	CLKNODEMETHOD(clknode_recalc_freq,	qcom_clk_fdiv_recalc),
91 	CLKNODEMETHOD_END
92 };
93 
94 DEFINE_CLASS_1(qcom_clk_fepll, qcom_clk_fdiv_class, qcom_clk_fdiv_methods,
95    sizeof(struct qcom_clk_fdiv_sc), clknode_class);
96 
97 int
98 qcom_clk_fdiv_register(struct clkdom *clkdom, struct qcom_clk_fdiv_def *clkdef)
99 {
100 	struct clknode *clk;
101 	struct qcom_clk_fdiv_sc *sc;
102 
103 	clk = clknode_create(clkdom, &qcom_clk_fdiv_class, &clkdef->clkdef);
104 	if (clk == NULL)
105 		return (1);
106 
107 	sc = clknode_get_softc(clk);
108 	sc->clknode = clk;
109 
110 	sc->divisor = clkdef->divisor;
111 
112 	clknode_register(clkdom, clk);
113 
114 	return (0);
115 }
116